1. Field of the Invention
The present invention relates generally to antennas for utility meters. More specifically the present invention relates to an untethered antenna for use in electricity utility meters configured for but not limited to wireless remote one way or two way communications for automated metering infrastructure (AMI) applications such as remote meter reading, remote connect/disconnect, home area networking, meter equipment firmware downloads, load management or location based services.
2. Discussion of Related Art Including Information Disclosed Under 37 CFR 1.97, 1.98
There are several known antennas adapted for use with electric utility meters configured for wireless remote automated meter reading. Some of the more relevant examples of embedded antennas are discussed below.
U.S. Pat. Appl. Pub. No. 20070085750 teaches traditional methods for locating an embedded antenna within the confines of a dielectric outer housing (the cover) of a utility meter. The system calls for discrete antenna elements with a permanently attached coaxial cable and connector for connecting the antenna to a radio modem. The antenna is mounted under the cover of the utility meter and attached to the inner body of the meter housing using plastic pop-fasteners.
U.S. Pat. Appl. Pub. No. 20060284784 describes a dielectric antenna housing that uses a flexible printed circuit antenna assembly and attaches to the meter body itself, again making use of a coaxial cable and connector to connect the antenna to the radio modem.
Alternative industry approaches are taught, for example, in U.S. Pat. No. 7,372,373, which discloses a slot antenna embedded into the printed circuit board of the meter electronics. However, such embedded antenna designs are taught in other references, such as U.S. Pat. No. 7,196,673, which explains that such designs degrade overall radio frequency system performance due to the proximity of the antennas to the noise sources within the meter.
While it is desirable, for both anti-tamper and vandal-proofing purposes, to mount the antenna within the confines of the utility meter dielectric cover, some references teach a means to optimize the radiating properties and efficiency of the antenna system, and thus improve the over-the-air performance of the system, by locating the antenna as far away as possible from sources of noise generated by the digital electronic meter circuits, and therefore generally as far towards the front of the meter as possible. In this regard, U.S. Pat. Appl. Pub. No. 20080129536 is exemplary.
Other background references, such as U.S. Pat. No. 7,196,673, teach approaches that include building the antenna onto the faceplate of the meter, attached to the meter inner body, in order to accomplish improved system performance.
In each of the aforementioned references there is an obvious effort to maximize the distance between the antenna and the meter electronic circuits, because the meter electronic circuits are a source of noise due to the mutual coupling into the antenna. Therefore, any design that further improves on the distance created between the embedded antenna and the meter electronics, while keeping the antenna within the confines of the utility meter cover, would be an advantage over the known embedded antenna systems and apparatus.
While the foregoing references show the general state of the art, as far as the present inventor is aware, no prior art references teach, nor do any formerly developed embedded utility meter antennas include, structure that comprises untethered antenna elements within the dielectric cover of the utility meter itself Thus, the foregoing prior art reflect the current state of the art of which the present inventor is aware, but reference to, and discussion of, the art is intended only to aid in discharging Applicant's acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the above-indicated prior art disclose, teach, suggest, show, or otherwise render obvious, either singly or when considered in combination, the invention described and claimed herein.